1.This research targets the headquarters of plural-form chain and franchising systems as the respondents to conduct the empirical survey.
本研究以我国双轨制之連锁加盟总部为调查对象，计回收66份有效样本。
2.The blockade and the nick type air defense adopt fire areas connection to form chain type air defense that used to the territory defense.
封锁式防空和阻击式防空一般采用火力区相互接壤而形成链式防空，链式防空用于疆土防御。
3.Interaction system of feeding and heating form chain safety protection system .
整机设有联锁安全保护：进油与加热系统联动。